Practice positive reinforcement as much as possible. For example, you can use cozy time as a reward, so bedtime becomes more enjoyable. Say something like “I really want to cozy up with you tonight, so please take a shower right away so we have time to do so. I will be very sad if we can’t cozy up tonight, so please hurry.” This will send a message to your son that he must listen to you or he won’t receive a reward. But the message is being sent in a loving and positive manner instead of being done so punitively. Hatzlachah with your efforts!